| Objective: In this study, cytologic localization of both transforming growth factor alpha (TGF-a) and its receptor (epidermal growth factor receptor, EGFR) in ovaries was determined and the levels of TGF-a in serum were measured in polycystic ovary syndrome (PCOS) and normal rat. The aim was to compare general and local action and to explore differences between PCOS and normal rat, which would help to explain further the failure of follicular development regulated by local factors, such as TGF-a, which is involved in the pathogenesis of PCOS.Material and method: 24-day-old immature female SD rats (n=60) were separated into two equal groups at random. One group was created PCOS animal model, another group was used as control. Being 36 days old, the rats were all killed. Blood specimens were centrifuged at 2000r/min for 20 minutes, the supernatant was collected for measuring TGF-a. Three ovarian specimens for each group were fixed in 4% glutaral for transmission electron microscope analysis. The rest of ovarian specimens were fixed in 10% formalin, dehydrated, and embedded in paraffin forimmunohistochemical staining (IH) of TGF-a and EGFR.TGF-a in serum was measured by RIA, a rabbit primary polyclonal antibody against human TGF-a, labelled by I25I, was used (Beijing Huaying Biology Institut). The sensitivity and specificity were high. A mouse polyclonal antibody against human TGF-a (CALBIOCHEM Company, USA) and a rabbit polyclonal antibody against human EGFR (SANTA CRUZ Company, USA. Diluted 1:150 before use) were used as the primary antibody in immunohistochemical staining.The intensity of immunostaining was evaluated by repeated staining of the same specimens and by more than two observers respectively. The primary antibodies to TGF-a and EGFR were replaced by PBS solution as the negative controls. Buffy drops in cells were regarded as the positive staining. Five sights were selected in 400x sight at random, and positive cells/all cells ratio was counted. It was graded as (-) for < 10%, (+) for 10-33%, (++) for 33-66%, and (-W-) for >66%.Statistics: RIA results were expressed as meaniSE. Comparison between groups was undertaken using paired /-tests. The x2 analysis was used to compare results obtained from IH. All data were analyzed with the SAS statistical program. P<0.05 was defined as statistically significant.Result: The levels of TGF-a in PCOS rats serum were significantly lower than those in normal rats (P<0.0001). The means of PCOS group and normal group were13.301+4.926pg/ml and 32.895+8.054pg/ml respectively.The theca-interstitial cells in PCOS rats were more than in normal rats. Immunostaining for TGF-a and EGFR was found in granulosa, theca and interstitial cells in all ovarian specimens. Staining for TGF-a in granulosa cells was significantly more intense in normal ovaries than that in polycystic ovaries (PCO) (P< 0.001), whereas similar in theca cells (P=0.508) and interstitial cells (P=0.127) between two groups. Immunostaining for EGFR in granulosa cells (P < 0.001), theca cells (P< 0.001) and interstitial cells (P< 0.001) were more intense in PCO than in normal ovaries significantly.In PCO, the intensity of immunostaining for TGF-a observed in granulosa and theca cells increased as the follicle became larger, but the intensity of immunostaining for EGFR in granulose and theca cells lasted intense strongly in all size of follicles, which was different from normal ovaries. In normal ovaries, the intensity of immunostaining for TGF-a and EGFR in granulosa and theca cells increased as the follicle became larger.In PCO, the granulosa cells were negative for immunostaining for TGF-a, and theca cells had weak staining for TGF-a, but the staining for EGFR in granulosa and theca cells were very intense. However, in normal ovaries, the moderate staining for TGF-a and EGFR was demonstrated in the same region.In PCO, interstitial cells had more intense staining for TGF-a than did theca cells, and theca cells had more intense staining for TGF-a than did granulosa cells. I...
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